Solar still



FIG. 1 is a perspective view of a solar still.

FIG. 2 is a left side elevational view thereof, the right side, front and rear elevational views are mirror images of the left side view.

FIG. 3 is a top plan view thereof; and,

FIG. 4 is a bottom plan view thereof. 

The ornamental design for a solar still, as shown and described. 